If what you want is an XFX, it really doesn't matter which one you get; just get the cheapest model, they all carry the double lifetime.
In terms of the factory OCed models, you can always OC yourself if you ever need the extra performance.
If what I want... I don't want XFX, I want the best and if someone else has a better card I'd love to hear about it. But if it's all the same, then I'd like to know that too.
I appreciate pepperman's advice, as can be seen in the fact that I thanked him. The above quote is what got me thinking. Is Sapphire better? MSI? ASUS? Or are they all the same/can I overclock them myself and get the same performance out of them?
What is most important to you? That I get my money's worth
For the most part, most manufacturers make the same card; the only difference is the name and the warranty.
That said, I personally prefer either XFX or Visiontek for ATI because of the lifetime warranty (and double for XFX).
Looking at newegg, currently the cheapest 5870 is $10 less than the standard XFX. The question for you is; is the double lifetime worth $10?
For some reason, it seems that the double lifetime warranty is something exclusive to the US? According to the sellers' site I only get 2 years of warranty here in Denmark. I'll have to look into this.
If you want something better than the reference board, there is the Gigabyte Ultra Durable and the MSI lightning. The MSI board is meant for more overclocking than the heatsink it comes with can handle and is a good choice if you want to put a water block on it. The Gigabyte Ultra Durable, which is the one I have, also uses a custom PCB and cooler and is the same setup they have on their planned Super Overclock 5870s.